The present invention relates to a powder circulation apparatus for circulating an absorbent media in the vicinity of a tire being subjected to wearing conditions such that the absorbent media entrains materials released from the tire and for conveying away the absorbent media and entrained released material.
A conventional pneumatic tire found on a passenger or truck vehicle is comprised of elastomeric materials such as, for example, cured rubber products. When the pneumatic tire is mounted on a vehicle, the tire is subjected to wearing during its rotation along a surface and is subjected to cyclic compressive and tensile forces. Due to such loading and wearing, particles are worn from the tire tread surface and, as well as, liquid-type materials are "secreted" or otherwise released.
Under typical, actual use conditions such as travel of the tire along a road surface, such released particles are immediately dispersed away from the tire and, accordingly, have negligible if not even virtually undetectable influence on the tire performance. However, there are other circumstances in which such material released from a tire may interfere with or mask the performance of the tire or hinder the acquisition of data concerning the tire. For example, tire manufacturers often test sample tires of a tire product line to thereby evaluate the tire's performance under anticipated or extreme load conditions or to detect manufacturing problems and such testing is often conducted on specialized tire test machines which rotate the tested tire at actual travel speeds while the tire is loaded by a rotating load wheel or endless belt. In such circumstances, the tire being tested does not undergo any translatory movement--e.g., the tire is simply rotated in contact with the load wheel or the endless belt at the same fixed reference contact area. The solid particles and liquid material released from the tire in such a situation tend to accumulate and circulate around the contact area and thereby hinder or falsely influence the test results.
One proposed solution for handling such released material is to introduce an absorbent powder or desiccant adjacent the tire which adheres to or absorbs the released material, thus creating particles of greater mass which fall onto a surface adjacent the tire contact area or disperse under the influence of the air currents moving around the rotating tire. These deposited particles, once clear of the tire contact area, then no longer unduly interfere with or hinder the acquisition of measurements of the tire and, also, such deposited particles are no longer susceptible to re-adhere to the tire tread surface and thereby falsely influence the tire measurement. However, the need still exists for an apparatus which effectively delivers such absorbent powder and which reliably removes the released materials from the tire contact area.